Some electronic power supply regulators may include over-current protection circuitry. Over-current protection may prevent catastrophic failure of regulator components, particularly power transistor output stages, in the event of a short circuit or a heavy loading condition at the regulator output.
Some power supply regulators may utilize a sense transistor to sense an overdrive condition and a current clamp to temporarily reduce the drive signal to the power output stage while the overdrive condition is present. However, sense transistor-based current clamps traditionally have poor direct current (DC) accuracy. Inaccuracies may be due to a combination of channel length modulation effects, sense element to pass element matching, and process, supply, and/or temperature (PVT) variations.